David Jummy, Bragazzi Nicola Luigi, Scarabel Francesca, McCarthy Zachary, Wu Jianhong
Fields-CQAM Laboratory of Mathematics for Public Health (MfPH), York University, Toronto, Ontario, Canada.
Laboratory for Industrial and Applied Mathematics, York University, Toronto, Ontario, Canada.
R Soc Open Sci. 2022 Mar 16;9(3):211863. doi: 10.1098/rsos.211863. eCollection 2022 Mar.
The attack ratio in a subpopulation is defined as the total number of infections over the total number of individuals in this subpopulation. Using a methodology based on an age-stratified transmission dynamics model, we estimated the attack ratio of COVID-19 among children (individuals 0-11 years) when a large proportion of individuals eligible for vaccination (age 12 and above) are vaccinated to contain the epidemic among this subpopulation, or the herd immunity (with additional physical distancing measures). We describe the relationship between the attack ratio among children, the time to remove infected individuals from the transmission chain and the children-to-children daily contact rate while considering the increased transmissibility of virus variants (using the Delta variant as an example). We illustrate the generality and applicability of the methodology established by performing an analysis of the attack ratio of COVID-19 among children in the population of Canada and in its province of Ontario. The clinical attack ratio, defined as the number of symptomatic infections over the total population, can be informed from the attack ratio and both can be reduced substantially via a combination of reduced social mixing and rapid testing and isolation of the children.
亚人群中的感染率定义为该亚人群中感染总数与个体总数之比。我们使用基于年龄分层传播动力学模型的方法，估计了在大部分符合疫苗接种条件的个体（12岁及以上）接种疫苗以控制该亚人群中的疫情，即实现群体免疫（并采取额外的物理距离措施）时，儿童（0至11岁个体）中新冠病毒的感染率。我们描述了儿童中的感染率、将感染个体从传播链中移除的时间以及儿童之间的每日接触率之间的关系，同时考虑病毒变体传播性的增加（以德尔塔变体为例）。我们通过对加拿大及其安大略省人群中儿童新冠病毒感染率进行分析，说明了所建立方法的通用性和适用性。临床感染率定义为有症状感染数与总人口数之比，可从感染率中得出，并且通过减少社交接触以及对儿童进行快速检测和隔离相结合的方式，二者均可大幅降低。
